The perioperative environment includes surgical operating rooms and related areas of hospitals and surgical centers. The perioperative environment includes but is not limited to: the operating room, one day surgery areas, trauma units, critical care areas, plastic surgery, neonatal intensive care, patient transportation, obstetrics, the post anesthesia care unit, radiology, X-ray, the electrophysiology lab, nursing services and the neonatal care unit.
During surgery, a patient may spend a great deal of time lying on a 20 inch wide surgical bed table where the patient is positioned by various devices, pads and cushions. Generally, hospitals provide fairly crude positioning devices for this positioning process. For example, patients may be propped into a selected operative position by rolled-up sections of bath blankets, disposable foam and surgical towels. However, these fairly crude positioning devices do not provide an acceptable degree of stability and do not facilitate appropriate safety as noted by the Association of Operating Room Nurses (A.O.R.N.).
Furthermore, for example, a rolled bath blanket used for a chest roll in the prone position can create peak pressure points that may cause capillary occlusion. A restriction of blood flow or capillary occlusion can cause post-operative decubitus ulcers and hence can require a long term costly physical therapy regimen. In addition, high interface pressure can lead to localized nerve damage, tissue damage or damage to muscles and bones.
The most common post-operative injuries are decubitus ulcers, also known as bed sores or pressure sores. Decubitus ulcers are wounds that form due to prolonged pressure on a particular point on the body, which constricts blood flow. Such pressure sores may result from a positioning device that creates high pressure (over 32 mmHg) against the skin. Once formed, pressure sores can take months to heal and can actually become life-threatening. The average cost to treat one Stage II decubitus wound is $40,000 to $50,000, according to the National Wound Care Association.
It is estimated that 23-25% of post-operative decubitus ulcers arise from damage that initially occurs due to high interface pressure on a specific area on the skin that occurs during surgery. The risk of decubitus ulcer development increases in patients that are prone to reduced circulation such as diabetics and the elderly. Decubitus ulcers lead to increased costs for medical care as well as increased cost that arises from potential medical malpractice claims; estimates of cost for this type of post-operative injury totals $2-$10 billion dollars per year.
Pressure ulcers may be a complication of immobility. The major cause of pressure ulcers is generally accepted to be an external pressure that occludes blood vessels (capillary occlusion).
Two distinct mechanical forces that contribute to pressure ulcers are a direct downward pressure and shear pressure.
Tissue Interface Pressure (TIP) is a direct downward vertical pressure, can occlude blood capillaries and cause ischemia to the area supplied by the affected vessels. Prolonged ischemia leads to cell and tissue death.
Shear Pressure is a horizontal force that occurs when the skin and underlying subcutaneous tissues are pulled taut and over-stretched, causing tissue deformity, obstructing blood flow and tissue necrosis.
Pressure and Shear will be higher in areas where soft tissue lies over bony surfaces. Forces over bony prominences should be reduced whenever possible.
Surgical procedures of greater than two hours and procedures that involve the cardiovascular system may cause an otherwise low risk patient to be at risk for harm. Patient positioning in surgery in general needs to be assessed carefully and surfaces used in positioning should meet recommended A.O.R.N. standards for positioning.
Positioning products commonly used by hospitals today include:
1. Reusable surgical towels.
2. Reusable bath blankets.
3. Disposable foam pads.
4. 2″ stitched surgical table pad.
5. Stitched, dipped and sprayed foam products.
6. Sheets, pillow cases and stitched pillows.
7. Various gel pads.
8. Rolled towels, sheets or bath blankets, often held with tape.
None of the presently used positioning products has been recommended as clinically sound for the positioning the patient by the U.S. A.O.R.N. (Association of Operating Room Nurses). In 2002, the A.O.R.N. declared positioning as a major safety concern in the perioperative environment.
Consequently, various cushioning devices or pillows have been developed for use in the medical field to alleviate dangers caused by rolled bath blankets, for example. Typical pillows or cushions are designed to provide support for a particular body part and have most often been produced for the following specific body parts: neck, head, foot and heels, sacral, trochanter, brachial plexus, and major surgical positions (supine, prone, lateral, Fowler and lithotomy). To provide such support, these cushions are sometimes constructed and designed to conform to the shape of the body part to be supported, too often with non-standard, inappropriate materials that are not tested for safe pressure outcomes, nor approved by the A.O.R.N for safe clinical practices.
Conventional stitched pillows are usually filled with a cushioning material of synthetic polyester, fiberfill or foam. Such pillows can be manipulated to conform to the shape of the body part to be supported. If the construction of the pillow is too firm, however, it becomes difficult to adjust the shape of the pillow to the body part. Conversely, if the pillow is too soft, depressions are easily formed, and the proper safe pressure of the body member is not achieved. Furthermore, the shaping capabilities of such conventional pillows are rather limited. Often, the filler simply packs into a dense mass and loses its resiliency. These positioners traditionally have stitched seams with rough edges that are exposed to the patient's skin, and thus also support the potential for cross-contamination after each use. Cross contamination can occur when pathogens such as bacteria or bodily fluids such as blood are trapped in the stitched seams or the thread itself. These products are cleaned and disinfected between surgical cases with low grade antimicrobials and are often used again for another procedure on another patient within fifteen minutes.
In response to the deficiencies of conventional filling material, inflatable cushions or pads have been developed. However, most of the prior inflatable pad cushions are very complicated structures that are costly to manufacture. Additionally, the prior inflatable cushions may be too firm, so pressure points and bed sores may still occur. Prior art inflatable cushions often also have stitched seams that may create pressure points and that may harbor pathogens.
Foam cushions may also create pressure points because the positioning cushions ‘bottom out’ due to inappropriate foam being used in combination with the correct foam thickness.
Accordingly, there exists a need in the art for improved positioning pads or cushions that are economical to use and that help reduce the potential for post-operative injury by providing safe interface pressures. Furthermore, there exists a need for such a pillow to be easily shaped or conformed to the desired configuration to provide support, while retaining sufficient resiliency to maintain the desired shape until it is intentionally changed by the user.